Add Members screen inconsistencies/CRASH

[Sagar0-0]

Guidelines

• I have searched searched open and closed issues for duplicates
• I am submitting a bug report for existing functionality that does not work as intended
• This isn't a feature request or a discussion topic

Bug description

Steps to reproduce:

1. Go to any Group Details and navigate to Add a new Member screen.
2. Try clicking on a contact multiple times, leading to adding and removing it from the selected members list.
3. This can cause some inconsistencies, like the total members count in the topbar, or the "Done" button being enabled or disabled.
4. If no new member is selected and the Done button is Enabled, then this can lead to the app crashing or unexpected behavior.

These inconsistencies can also be seen when creating a new group. The topbar and the "Next" button can behave weirdly or not expected.

Possible Solutions:

1. We might have to change the behavior of how we are updating the UI state. We are using SimpleTask.run to update the UI states, which is causing the issue, I am investigating this and will update the comments when I have solved this.
2. Simply Add an additional check when clicking on the done button, although the Precondition is already there but this does not help the user or UI, it just closes the screen as shown in the video.

Screenshots

document_6300953998052561959.mp4

Device

Realme GT NEO 3T

Android version

14

Signal version

7.28.4

Link to debug log

https://debuglogs.org/android/7.28.4/5ad56851355873fcf53a0171424f0dde3f31689ebfd4bc20c762b5f9a761895d

[Sagar0-0]

There are 3 issues with this screen AddMembersActivity.

1. The topbar has inconsistent Contacts count from getTotalMemberCount function.
2. The Done button is enabled even when no new member is selected.
3. The contactsFragment.getSelectedContacts() doesn't always send the latest value to the done button, which causes the Exception.

Improvements in the ContactSearchMediator#SelectedContacts should solve the issue.

[Sagar0-0]

My recommended approach is to use the contactMediator.getSelectionState() to get the livedata and observe it directly on the ContactSelectionListFragement. (The activities needing the selected contacts list are not the right place to observe onto this LiveData as they depend solely on the Fragment for any Contacts list updates).
Although the problem still exists If we replace the observed State with the contactSearchMediator.getSelectedContacts() at all places in ContactSelectionListFragement. So, I believe these two selectionStore.state and selectionStore.stateLiveData#latestValue always gives same result at the same time.